Retrieval of images from a relatively large collection of reference images remains a significant problem. It is generally considered impractical for a user to simply browse a relatively large collection of images, for example thumbnail images, so as to select a desired image. Traditionally, images have been indexed by keyword(s) allowing a user to search the images based on associated keywords, with the results being presented using some form of keyword based relevancy test. Such an approach is fraught with difficulties since keyword selection and allocation generally requires human tagging, which is a time intensive process, and many images can be described by multiple or different keywords.
Alternative approaches have been proposed utilising a processing system to perform Content Based Image Retrieval. However, such an automated task can be quite difficult for a processing system to perform accurately. For example, if we consider four bi-level images shown in FIG. 1, and consider techniques such as the comparison of colour histograms or the comparison of edge features, we find that such techniques for each image return very similar measures, thus leading to a false positive conclusion indicating that the images include substantially similar content when clearly they do not.
Therefore, there is a need to provide a method, processing system, and/or a computer program product which overcomes or at least ameliorates the above mentioned disadvantages.
The reference in this specification to any prior publication (or information derived from the prior publication), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that the prior publication (or information derived from the prior publication) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.